isicom: redo locking to use tty port locks
Alan Cox [Fri, 2 Jan 2009 13:45:26 +0000 (13:45 +0000)]
This helps set the basis for moving block_til_ready into common code. We also
introduce a tty_port_hangup helper as this will also be generally needed.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/isicom.c
drivers/char/synclinkmp.c
drivers/char/tty_port.c
include/linux/tty.h

index a449449..db53db9 100644 (file)
@@ -841,7 +841,6 @@ static int isicom_carrier_raised(struct tty_port *port)
 static int block_til_ready(struct tty_struct *tty, struct file *filp,
        struct isi_port *ip)
 {
-       struct isi_board *card = ip->card;
        struct tty_port *port = &ip->port;
        int do_clocal = 0, retval;
        unsigned long flags;
@@ -876,11 +875,11 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
        retval = 0;
        add_wait_queue(&port->open_wait, &wait);
 
-       spin_lock_irqsave(&card->card_lock, flags);
+       spin_lock_irqsave(&port->lock, flags);
        if (!tty_hung_up_p(filp))
                port->count--;
        port->blocked_open++;
-       spin_unlock_irqrestore(&card->card_lock, flags);
+       spin_unlock_irqrestore(&port->lock, flags);
 
        while (1) {
                tty_port_raise_dtr_rts(port);
@@ -905,14 +904,13 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&port->open_wait, &wait);
-       spin_lock_irqsave(&card->card_lock, flags);
+       spin_lock_irqsave(&port->lock, flags);
        if (!tty_hung_up_p(filp))
                port->count++;
        port->blocked_open--;
-       spin_unlock_irqrestore(&card->card_lock, flags);
-       if (retval)
-               return retval;
-       port->flags |= ASYNC_NORMAL_ACTIVE;
+       if (retval == 0)
+               port->flags |= ASYNC_NORMAL_ACTIVE;
+       spin_unlock_irqrestore(&port->lock, flags);
        return 0;
 }
 
@@ -1034,9 +1032,9 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
 
        pr_dbg("Close start!!!.\n");
 
-       spin_lock_irqsave(&card->card_lock, flags);
+       spin_lock_irqsave(&port->port.lock, flags);
        if (tty_hung_up_p(filp)) {
-               spin_unlock_irqrestore(&card->card_lock, flags);
+               spin_unlock_irqrestore(&port->port.lock, flags);
                return;
        }
 
@@ -1054,12 +1052,12 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
        }
 
        if (port->port.count) {
-               spin_unlock_irqrestore(&card->card_lock, flags);
+               spin_unlock_irqrestore(&port->port.lock, flags);
                return;
        }
        port->port.flags |= ASYNC_CLOSING;
        tty->closing = 1;
-       spin_unlock_irqrestore(&card->card_lock, flags);
+       spin_unlock_irqrestore(&port->port.lock, flags);
 
        if (port->port.closing_wait != ASYNC_CLOSING_WAIT_NONE)
                tty_wait_until_sent(tty, port->port.closing_wait);
@@ -1076,22 +1074,22 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
        isicom_flush_buffer(tty);
        tty_ldisc_flush(tty);
 
-       spin_lock_irqsave(&card->card_lock, flags);
+       spin_lock_irqsave(&port->port.lock, flags);
        tty->closing = 0;
 
        if (port->port.blocked_open) {
-               spin_unlock_irqrestore(&card->card_lock, flags);
+               spin_unlock_irqrestore(&port->port.lock, flags);
                if (port->port.close_delay) {
                        pr_dbg("scheduling until time out.\n");
                        msleep_interruptible(
                                jiffies_to_msecs(port->port.close_delay));
                }
-               spin_lock_irqsave(&card->card_lock, flags);
+               spin_lock_irqsave(&port->port.lock, flags);
                wake_up_interruptible(&port->port.open_wait);
        }
        port->port.flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
        wake_up_interruptible(&port->port.close_wait);
-       spin_unlock_irqrestore(&card->card_lock, flags);
+       spin_unlock_irqrestore(&port->port.lock, flags);
 }
 
 /* write et all */
@@ -1430,10 +1428,7 @@ static void isicom_hangup(struct tty_struct *tty)
        isicom_shutdown_port(port);
        spin_unlock_irqrestore(&port->card->card_lock, flags);
 
-       port->port.count = 0;
-       port->port.flags &= ~ASYNC_NORMAL_ACTIVE;
-       tty_port_tty_set(&port->port, NULL);
-       wake_up_interruptible(&port->port.open_wait);
+       tty_port_hangup(&port->port);
 }
 
 
index fcf1ec7..1f5c21e 100644 (file)
@@ -3331,6 +3331,17 @@ static int carrier_raised(struct tty_port *port)
        return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;
 }
 
+static void raise_dtr_rts(struct tty_port *port)
+{
+       SLMP_INFO *info = container_of(port, SLMP_INFO, port);
+       unsigned long flags;
+
+       spin_lock_irqsave(&info->lock,flags);
+       info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+       set_signals(info);
+       spin_unlock_irqrestore(&info->lock,flags);
+}
+
 /* Block the current process until the specified port is ready to open.
  */
 static int block_til_ready(struct tty_struct *tty, struct file *filp,
@@ -3381,12 +3392,8 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
        port->blocked_open++;
 
        while (1) {
-               if ((tty->termios->c_cflag & CBAUD)) {
-                       spin_lock_irqsave(&info->lock,flags);
-                       info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
-                       set_signals(info);
-                       spin_unlock_irqrestore(&info->lock,flags);
-               }
+               if (tty->termios->c_cflag & CBAUD)
+                       tty_port_raise_dtr_rts(port);
 
                set_current_state(TASK_INTERRUPTIBLE);
 
@@ -3793,6 +3800,7 @@ static void add_device(SLMP_INFO *info)
 
 static const struct tty_port_operations port_ops = {
        .carrier_raised = carrier_raised,
+       .raise_dtr_rts = raise_dtr_rts,
 };
 
 /* Allocate and initialize a device instance structure
index 0557b63..9f418bc 100644 (file)
@@ -7,6 +7,7 @@
 #include <linux/tty.h>
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
+#include <linux/serial.h>
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/slab.h>
@@ -96,6 +97,29 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
 EXPORT_SYMBOL(tty_port_tty_set);
 
 /**
+ *     tty_port_hangup         -       hangup helper
+ *     @port: tty port
+ *
+ *     Perform port level tty hangup flag and count changes. Drop the tty
+ *     reference.
+ */
+
+void tty_port_hangup(struct tty_port *port)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&port->lock, flags);
+       port->count = 0;
+       port->flags &= ~ASYNC_NORMAL_ACTIVE;
+       if (port->tty)
+               tty_kref_put(port->tty);
+       port->tty = NULL;
+       spin_unlock_irqrestore(&port->lock, flags);
+       wake_up_interruptible(&port->open_wait);
+}
+EXPORT_SYMBOL(tty_port_hangup);
+
+/**
  *     tty_port_carrier_raised -       carrier raised check
  *     @port: tty port
  *
index 5001bbc..a1a9314 100644 (file)
@@ -438,6 +438,7 @@ extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 extern int tty_port_carrier_raised(struct tty_port *port);
 extern void tty_port_raise_dtr_rts(struct tty_port *port);
+extern void tty_port_hangup(struct tty_port *port);
 
 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 extern int tty_unregister_ldisc(int disc);